Bottom dump apparatus



Jan. 8, 1935. H. w. SANFORD 1,986,943

BOTTOM DUMP APPARATUS Fil ed Aug. 15, 1952 a Sheets-Sheet 1 attorneys H. w. SANFORD BOTTOM DUMP APPARATUS Jan. 8, 1935.

Filed Aug. 13, 1932 8 Sheets-Sheet 2 (Ittotneg 6 Filed Aug. 13, 1952 8 Sheets-Sheet 5 Zhweutpr Me 144 Gay/ 090 attorney;

H. W. SANFORD BOTTOM DUMP APPARATUS Jan. 8, 1935.

Filed Aug. 13, 1932 8 Sheets-Sheet 4 3nventor Away/K 6/7A/F0/90 'Cittorneg s Jan. 8, 1935. H. w, SANFORD 1,986,943

BOTTOM DUMP APPARATUS Filed Aug. 13, 1932 8 Sheets-Sheet 5 Jan. 8, 1935. H w AN D 1,986,943

BOTTOM DUMP APPARATUS Filed Aug. 13, 1932 8 Sheets-Sheet 6 3 nventor flaa/s WSW/VFO/PD Jan.8,1935. W ANFORD T 1,986,943

BOTTOM DUMP APPARATUS Filed Aug. 13, 1932 8 Sheets-Sheet 7 H. w. SANFORD BOTTOM DUMP APPARATUS Jan. 8, 1935.

Filed Aug. 13, 1932 8 Sheets-Sheet 8 a Patented Jan. 8, 1935 UNlT-ED STATES PATENT OFFICE ilma-.943 j :3

BOTTOM pp APPARATUS H Hugh Sanford, Knoxville, Tenn.

p 'Application August 1s, iosaserial No. 628,741

' 50 Claims} (01. 105 -253) This invention relates to improvements in apparatus having drop bottomdoors which are released for du'mpingso thatthe contents of the apparatus may be discharged downward past such 5 doors, and particularly to apparatus in which a plurality of such doors are held closedthrough the agency of a single latch mechanism, but can open at a dumping point in succession from the front rearward. I j r One of thefeaturesof the present inventioni's the provisionof an apparatus having doors which may swing downward for an opening movement whereby material may pass such downwardly swung door, in conjunction with amove 1; mental: a right-angle to the dooraiiis whereby the door operates to free another doorf'forthe opening movement of the latter, togetherwith devices wherebyapclosingmovement of the door by upward swinging about ;it s,axis will likewise 20 occasiona return movement of theQdoorkin adirection at a right angle to its axis whereby said devices are brought into position. for supporting the other door. I f f r Another feature of the present invention is the 23 provision of a traveling apparatus. having aplu rality of doorsadapted to swing about axes transverse to the line of movement of the apparatus, and in which at least oneofsaid doors is permitted a movement forwardly and rearwardly 30 with respect to.the apparatus while .it is swinging for opening andclosing, in conjunction with door guides which cause a forward movement of .the door as itmoves toward closed position.

.A furtherfeature of the present invention is the provisionof such doormoving means as interengaging wedging or cam members on thedoor and frame. v o H Still another feature'of the present invention is the construction of the door in which a simple 10 doorstructure is provided adapted for pivotal swinging movement abouta 'rod'secured to the frame, the door being provided with means for permitting a sliding movement of the door with respect to said rod, sothat the door may move in a direction ata rightangle to the axis of the rod during its swinging movement,and thereby move. from and tea securing relationship with respect to another door.

.Still another. feature of thepresent invention a is the provision of .anfapparatus comprising a pluralityof bottom doors of which at least one is supported pivotallyona pendulum-like member, and by its pivotal movementjis adapted to open, and by the 'swingingmoveinent of the pendulumf like member is adapted to enter into securingre lationship with respect to a 'door located more closely to.the front of theapparatus: in'some cases in conjunction with means operated by such forward K door for rocking the" pendulum-like member into its securing position as the forward *5 door moves to its closed position. a l Further features forming objects of the-present invention are set forth in the following specification and claims, in conjunctionwith'the illustrative forms on the accompanying drawings} 10 In these drawings: V

"Figure 1 is. a vertical" longitudinal .section through'a vehicle of the type mentioned, illustr'ate'd as a mine or industrial car, having two axles on its frame for supporting the wheels, and with doors located in front, between and behind theseaxles. a

Fig. 2 is a corresponding view, on'a larger scale, showing therelationship of a forward door and a rearward door, together with the devices for moving" the rearward door into a forward position upon closing whereby it may secure the forwarddooragainst opening. 4

Fig. 3 is a similar view showing the rearward door in open position.

Fig. 4 is a vertical transverse section of a frag ment of the structure, substantially on line 4+5 of Fig.2. a

"Fig. 5 is a sectional view of a fragment, sub- 'stantially on line 5-5 of Fig. 2.

'Fig. 6 is a view corresponding to FigJ-l, but illustrating a modified form of door construction. Fig; '7 is a detail view, on a larger scale, of a portion' of Fig. 6. I,

Fig. 8 is a View corresponding to Figs. 1 arid 6, but showing another modified form. v b Fig. 9 is a view on an enlarged scale of the portion of Fig. 8. v

"Figs. 10, 11,12 and 13 are fragmentary views corresponding to 1, and show further modified forms of door system. A Figs. 14-and'l5' are fragmentary views, showing further modified forms of the'door: system.

Fig. l6is a side elevation, showing the employment of the invention in a conveyor.

Fig. l'lisja fragmentary plan view of the operative flight of the same. a b

Fig. 18 is atransverse sectional View, showing the conveyer in conjunction with a loading de- In the form shown in Figures 1 to 5 inclusive, the car is shown to have sidesills 10 having .upwardlylextending body plates 11 and end plates 12.:The axles 13 for wheels-W are supported by suitable means (notshown) in the side sillslO,

the pressure of the lading. The front door 15 may be mounted by pivot members 16 fixed to the side sills 10, and extends from side to side of the car so that, in the closed position shown in Fig. 1, it serves to retainabove it a corresponding portion. of the ladingin the car. The central door 17 and rear door 17a may be alike in shape and are each supported on transverse g pivot rods 18 (Figs. 2, 3 and 5) located, beneath the corresponding angle member 14, in the slots 19 of lug plates 20 which are secured to the transversely extending connecting piece 21 and thus to the pendulum members 22 which at their upper ends pass through apertures 23 in the angle members 14. The lower ledge 24 of a transverse angle member 21 engages beneath the rear edge of the next forward door 15 or 17 to hold the same against downward opening movement.

Each of the doors is illustrated as comprising a single sheet of metal having an upturned stiffening lading-retaining flange at each edge, and

being bent upwardly to'provide an abutting nose 25 at itsforward and upper edge. The transverse pivot rod 18 is illustrated as located above this sheet, and securing and stiffening members 26 are fixedly secured to the door sheet, conform to the pivot rod 18, and at their forward upper portion closely join. the nose 25. At the sides, the door sheet is provided with upwardly extending cam members 27 whichengage'with the rollers 28 mounted by fixed pivots 2801. on the side sills 10. Pins 18a: (Fig. 5) prevent endwise disengagement" of the rods 18.

At the rear edge of the rear door 17, at the rear end of the car, is provided some suitable latching means 30, for retaining the rear door in its raised and closed position.

In operation, the car is filled with lading, andis drawn over rails R to a discharge point at which the latch 30 is tripped whereby to release the rear door 17 and permit it toswing downwardly about its pivot. In dropping down upon the ties, or upon the material already present at the discharge point, a frictional rearward drag is exerted upon this rear door 17. As the door swings downward about its pivot 18, the nose 25. leaves the pendulum piece 22, and thereupon the weight present upon the middle door 17, the weight of the pendulum members and associated parts, and the frictional drag aforesaid, causes the pendulum members 22, the transverse piece 21, and its web 24 to swing in a clockwise direction (Fig. 2) toward the position shown in Fig.3 in which the web 24 has released the middle door 17. 'Ihismiddle door 17 therefore is free to drop about its pivot rod -18 and in turn and in like manner releases the front door 15.. As each door opens, it swings about its pivot 18 or 16 and the rear and middle doors likewise may travel lengthwise with the pendulum members 22. By the provision of the slots 19 for the ends of the pivot rods 18, however, as the nose 25 tends to move rearwardly away from the corresponding pendulum members 22, the latter are forced in a clockwise direction. for the reasons aforesaid, and may rock independently of the rearward movement of the transverse rod 18, so that a quick opening of the door is attained, corresponding to a very small angular movement about the axis of the pivot rod 18.

As the doors discharge and pass from the discharge point, they individually ultimately come to the position shown in Fig. 3. During the further transit of the car (toward the right in Fig. 1) each of the doors is brought against the closing device C which is located along the right of way, between the rails R, and thus the door is automatically raised into its closed position. For example, as the front door 15 is raised it is brought: to the position ofnormal closure, and thereafter is held supported in such position by a horizontal portion I-Iin extension of the device C. The middle door 17 is then raised by the device C untilit likewise moves into closed position. During this movement, the door swings around its pivot rod 18 until the nose 25 engages the web 24. engages beneath and secures the front door 15 against downward opening movement. By reason of the slots 19, this movement of the pendulum members 22 is assured, regardless of whether thepivot rod 18 is in the front portion of the slots 19 or not. In'this condition of the parts it will be noted that so long as the middle door 17 is in its-closed position, any tendency of thependulum members 22 to move clockwise is'resisted by the nose 25 which is held in proper raised position by the engagement of the transverse rod 18 against the walls of the slots 19, and the nose 25 is'likewise held against rearward movement by the engagement of cam 27 with rollers 28..

The middle door 1'7 is temporarily held in its closed position by the horizontal portion H in extension of the device 0 until the rear door 17a is likewise swung open into its closed position and engaged by a latch 30. A similar operation occurs at thisrear door, so that the transverse web 24 on the pendulum members 22' of the rear door operates now to secure the middle door 17 in closed position.

Thus it will be seen that each door is individually moved to closed positionby the device C, and then is latched during the closing of the next rearward door; and that eachdoo-r in closing moves to the position in which it is' to remain duringtransport of lading, so that the effort required forclosing each door involves that of raising it and. moving it forward into its proper closed position.

In the form o f.construction shown in Fig. 6, the side sills 10 and. other parts are provided as before, and the'front door 15a is carried by a fixed pivot 16a. The middle door 172) is formed of a metal sheet having lateral stiffening and lading supporting flanges, and at its forward edge is bent downwardly and rearwardly at 37 to provide an open loop which embraces the transverse pivot rod 18alocated between the side sills 10 and resting in slots 38 of stiffening pieces 39.attached to the side sills. These stiffening pieces 39 are connected to the angle members 14 and have apertures 40 through which the car faxles and their usual collars may be passed for insertion in or removal from the car. The rearward stiffening pieces 39are providedpn the lower portion of their front .edges' .with inclined surfaces 41xfor engagement by the pieces 42.secured.to thellateral flanges of thedoor sheet 17a. l l At the rear. of the cariis provided a 1atch43" with a blocking .member 43aforengaging and holding the rear edge of the rearl door 170 in closedlposi- .tion. This rear" dOOIxiS Llikewise provideduwith pieces 42a for engagement Lduringi the .final closing movement-with. the surfaces 41 on .end pieces44. i i i .i

In operation,with the frontand middle doors in *theposition shownin Fig. 6, and the-rear! door swung to closed position and secured by latch 43, the car may support itslading andzbe transported over rails R tothe rdischargeapointpat which the latch 43 is released. By. this release of the latch, the rearward door 170 is :free to swingidow'nward as before, and by the :frictional drag aforementioned and also by itsnweight, it also.slides.:along rod 18a rearward relative .to the side sills .and passes from the position shown insFig. 7 into that shown in .Fig. 6. .This combined .swinging and sliding movement quickly'releases the'rear edge of the middle door 17b whichhas theretoforebeen supported upon the rear TdOOI 170 so thatthe latter in turn may swing downward and move relativelycrearward and .in turn release the front door 115a. With "a dump car, for example, all doors may be thus released before the front door arrives at an emptypart of the discharge bin. The doors thereupon discharge their lading in 1-2-3 order, and'theifrontdoor is not held closed until its .ladingmust :fall a great distance'to the bottom of the :bin. .Thedischarge offthe la'ding thus occurs. Each door is then engaged by the closing device C and-raised into closed positionas before, being momentarily heldtherein'by the sponding .door into its normal :holding 'relationship with the next forward door (respectively the.

frontidoor. 15a and the middle door-17b inFig; 6). In this 'form, also, thismovement occurs independently of the closing of any other door; When finally the rear door 170 is raised, it in turn is moved forwardly to hold themiddle door 1% in secured position and is itself latched by the latch 8. The car is thenready for further trans portof lading. .Each bodily movabledoor is held in its 'forward bodily moved position by an element fixed to the frame and engaging the door adjacent its-rear edge. v

In the particular form of construction shown in Figs. fiand Lit will'be notedthatthe parts are so arranged that the doors, axles and pivot=rods 10, one wheel is removed,land then the axle and its collars may be slid 'tran'sversely out of' 'ftlie car. The door andits pivot lSaLmay then be slid up; wardly and rearwardly along the slots'38,and then the rod 18a drawn transversely outof the car,

whereupon the door 'is'lfree. It is also, however, possible to remove a door without firstremoving the corresponding.axleiandpivot rodllla. As shown in Fig. 7, it is possibleatanyplace -where"there is freedom between itherails-for adoor to swing freely, to rock a. "doorisuch' as 1721 in a counter clockwise direction about its pivot rod 18a into the positionshown in dotted lines in Fig. .7, raising the next forward door to permit this movement ifinecessary, and then slidingtne door which is tobeiremoved in a rearward direction until its 1 endsz37 clears the pivot rod- 18a, whereupon the door drops free from the car. Thus it is easy to replace axles, pivot rods and doors if these beycomendama'ged or worn.

In the form of execution in Figs. 8 and 9, the axles 13b extend as before through the side sills 10. Each of these axles is provided, adjacent the side sills 10, with the pendulum members 22a :whichare providediwith arcuate slots 45 for receiving the fixed stops .46 on the side sills 10. At thelowerend of eachpair of pendulummembers is provided a transverse pivot rod 18?) for the corresponding door. The front door715b is mounted on the fixed pivot 16b. The middle andrear doors 17d, We are mountedon the transverse rods 1812. :A latch 43b. is provided to receive and secure the rear edge of the rear door l'le.

In operation, this form of construction, with thebottom doors closed and the bodily movable doors heldin forward position, upon the release of :latch 431), permits a dropping of the rear door 176, andtherewith the frictional rearward dragging effect upon the door as before, assisted by the pressure of the middle door 19d and its lading, causes a clockwise movement of the rear pendulum members 22s. This in turn results in a dropping of the middle door 17d, and in sequence a rocking of the forward pendulum means 22a so that the front door 151) may drop. Normally, all doors .are thus released before the front door passes over the. discharge bin, so that each successive door opens fully only as it comes to an empty part of the bin. When the load has been discharged the'car in its passage over the track side car member C and the extension H causes a raising of the front door 1517 into closed posi-. tion (Fig.8) where it is held at .least until the middle door 17d has also been raised. In the form of construction shown the engagement of thecamming noses at the rear edges of the side flanges of the front door 15b with the wedging or forcing surfaces provided at the front edges of the pendulum means, causes a counterclockwise rocking of the pendulum and therewith a bodily forward movement of the middle door 1711, until the front edge of this middle door 17d engages beneath the front door and holds the latter against later dropping. As the middle door 17d is raised on contact with the closing device C, it

may-also engage with a similar wedging or forcing surface provided on the rear pendulum means 22a whereby also to produce a forward movement of the middle door 17d, and also to occasion a counterclockwise movement of the rear pendulum means 22a for moving the rear door 17c bodily forward, so that this rear door may then retain the middle door 17d in closed position. Finally the rear door is latched by the device 43b in usual manner.

In the form shown in Fig. the axles 130 are mountedas before with respect to side sills 10. Over each axle fits a pendulum piece 22b which has a curled upper or rearward end adapted to fit the eof-responding axle and to move concentrically about it. The forward door is mounted on a fixed pivot 16c. The middle door 171* and the reardoor 179" are each provided with upwardly and rearwardly rebent portions which em sayemsrace the transverse rods 18c. In this form of construction, there are provided for eng'agement with the rear edges of the middle and rear doors the wedging or forcing pieces 44c, 44d which operate toforce the corresponding doors forward during their closing movement. The forcing piece 440 is shown as connected to a side sill l and as being provided with an upwardly and forwardly inclined slot in which the rear rod 180 may move. A. piece. 440: adjacent the forward axle is provided with a similar slot for the forward rod 180. In operation, the structure according to Fig. may be loadedwith its doors in closed position andthe rearward door 179 held by a latch 43c. Upon arriving at a dumping point, this latch is released and thus the rear door 17g is permitted to drop and move rearward, its rod 180 sliding downward and backward in the corresponding slots of the pieces 440 until the rod attains the position shown in 18c, being assisted in this movementby friction-as before, and by inclination of the slot itself. This movement withdraws the rod and door portion from its former position,

in which these were in supporting relationship to the pendulum pieces 22b, and thus the piece moves to the position shown adjacent the rear axle in Fig. 10, so that the middle door 17f may now likewise drop and make a rearward movement whereby to release the pendulum piece 221) at its forward edge, and thus in turn release the forward door 150. After discharging the lading, the forward door 150 encounters a closing device C as before, and is swung into its closed position about its fixed pivot 160. A moment later, the middle door 17f is likewise swung toward its closed position by the same closing device, and

' in its closing movement encounters the forcing the forward door 150.

surface of the piece 440 and is thus moved forwardly so that the rod 180 thereof travels forwardly and upwardly in the corresponding slots and pushes the corresponding pendulumpiece 221) into holding engagement with the rear edge of In turn, the rearward door 17g is moved into closed position, being forced forward by the forcing surface of the piece 44d, so that it also presses its corresponding pendulum piece 22b into holding engagement with the middle door 17], and is itself latched by the latch 43c. During these operations the respective doors have been closed by the horizontal extension H of the closing device C. After the latch 43c operates, the car may be returned to the mine or other point for reloading.

In the form of construction shown in Fig. 11 the side sills 10 are mounted with respect to the axles 13d, and in the illustrated form each axle has an angle iron 14b extending across the same and serving as a support from which are suspended the pendulum pieces 220 having the ledges 240 for engaging the corresponding doors. The front door 15d is mounted on a fixed pivot 16d. The middle doorl'lh is mounted by pivot connections 18d to the corresponding pendulum pieces 22c and their ledge 240. The rear door 1'71 issimilarly mounted by a pivot 13d. A forcing piece 442 is attached to the frame adjacent the rear axle and is provided with a forcing surface for moving the middle door 17h forward as it closes. A forcing piece 44f near the rear end of the car performs a similar function forthe rear door 172'.

The method of operation is the same as described above, in conjunction with the latch 43d for the rear door. In thisform of construction it 'frame for limiting the rearward movement of the axles 136 which are illustrated as having bearing 1 members 13:1: of semicircular external shape above them. The front door 15e is mounted on a fixed pivot 16a. The middle door 1770 has its forward edge bent upwardly and backwardly, so that it fits over the front axle and also the bearing members 133:. A spacer member 133 holds the free edge of the door structure in proper position, and prevents separation of the door from the axle. The rear door 17Z is similarly mounted upon the rear axle 136. The frame supported member 44g has a surface for forcing the middle door forward as it moves to closed position, and a similar piece 44h is provided at the'rear end of the car for the rearward door. 171. Mounted on the middle and rearward doors, adjacent the rebent portions thereof, are the securing pieces 61, which in the closed position of the doors serve to support each the next forward door.

The operation of this door system during discharging and relatching is substantially the same as before. Each door is closed and brought to its final lading-holding position before the door located to its rear is brought into lading-holding position. When all doors are finally returned to the lading-holding position, a latch 436 may operate to hold the rear door, and each door then operates to secure the door in front of it in proper position ready for immediatev discharge.

In the form. of construction shown in Fig. 13, the doors are substantially of the type shown in Fig. 12, except that the supporting members 61 are omitted. In lieu thereof, the transverse rods 18 support pendulum pieces 22 which have ledges 24f at their lower edges. to support the next forward door. Each sliding door in this instance operates substantially in the manner al ready described in Fig. 10.

In the form of construction shown in Fig. 14 the front door 15m is mounted on a fixed axis 16m. The middle door 17m and the rear door 17n have rebent front edges of the form shown in Figures 6 and 7 which fit over the transverse supporting rods 13m which may be the axles of the vehicle. These doors therefore have both the swinging and the sliding movement as described for the form of construction shown in Figures 6 and 7. The structure of the rear door 1711, includes filler pieces 17a: which are of wedgeshape and extend, when the door is being dragged along a bottom drag rail RX after dumping, to present a surface for engagement by the rear edge of the middle door 17m as the latter is swung upward toward closed position by the closing device C as before. Above the filler pieces 17:11 is a stop 39:1: on the apparatus frame. In operation, the doors are released for dumping as described before, by the release of the latch 43m. As the front door 1.5m strikes the closing device C, it is swung upward into the position shown in Figure 14. As the middle door 17m encounters the closing device, it is likewise swung upwardly, but during its closing movement encounters the forwardly presented surface of the open rear door 17n and thereby is given a forward bodily movement relative to the frame of the apparatus so that it successively moves into the positions shown in dotted lines in Fig. 14. It will be noted thatthe surface of the filler pieces. l'ix'perniits a smooth transfer of therearedge of door 17m from the filler piece to the stop 393:. When the reset-re:

7 rear edge of door l'fm rests against stop 39rc it is in engaging position withf-the-forw ard door 15 m and thus prevents opening of'ithisdoor: and it" itself is held in closed and forwardlymoved po '5 sition by the fixed stop 39fici Asthe re r doorivn I movement. Themiddle-' and rear doors; I7 I'Zqare provided at theirforward edges wit mem-- ceiving portion of ethe ear dumping movementl "A fter dumping; the front the U portion being directed at a "considerable angle to the general ez'rtensi'on of the 'l'ading' 're' 4 responding door. *A fixed stop 62 {is provided for-holding" the middle door 17p in a relatively forward-13f moved position when closed, 'ancl the'- latch 43p likewise secures the rearwarddoor when closed in a clesed and forwardly moved position." In operation-,-f-release of--the latch 4sp ermits downwardlswingmg and hodily' rearward movement suceessivelyofthe rear door 17g andthe middle door 17p whereby the middle door and fiont door-"are released for door 15p encountersthe closing deviceC 'a's hefore and is moved to the olosedpos'iti-on shown in Fig? 15. As themiddle door 1:772 eneounters the en ine device, it isgiven a teeny movement relative to 7 1? the frame substantially in the direction of the with the-bight.ofit s"' u brt ion corresponding pivot liipg As it i closing device C, it arses moved bodily" and wung in"ful1--1inesinte tliatshown dette lin'es pinto the 1 where it in q the rear edge I v V v latter closed" and in" engagementthe' stop raised from its former position infwhich the-piv'et' 13p thereof was engaged' at the" t t es the U portion into the "os'ition show n-*fulllines% in-- iig. 15; Further"rnovement of the-apparatusrelf causes a {swinging ative to" the closihg device" G the position Show of i the middledoor- 175 fr which it presents the bight of the -U portieinbe+ neath the rear edgeof the forward 'door 15p tot hold the latter olo The"rear; door-1' 1 "s shown" in full linesi 1 s fully:-Opehedpbsiition sting'upomthe;

ncounters" the closedget-ted line position eerig? turn presents it's' portionf-"heneath of the rriiddle-doorlflp to holdthe 62 which prevents-any bodilyinovernerit "of this door. Finally the rear door 17a is engaged by; the latch 43p which prevents? swinging or 'hodily' movementof this doorg J 1 From the form of *cohstruetioh shown in Figures 16, 1'7 and 18* it willbe notedthat thed'oor system is not limited to a dump, vehi'el'e' having' road or rail wheels," but a that it be employed in a c-onveyer system be prisingarrendless chain oi drop-botto-m doors. "l jljj The shaft '70 supports asprocketfwheel"71; which may engagewiththewheels wwand' trans for these wheels from-lower "guide railsf'is to upper guide rails 7415f \Rfhile thefwh'eels are en gaged with the lower guidefrails" 73} they are moving in the oon eyingFfiightI-"The'axles 74 of these wheels pro fjde pivot rodsforthe nesting link memhersjfw and fonthebodvsides conveyer', Drop bottom doors 77, 78 and v h a l s 7 4; c r o d n n construction and arrangement {with the drop bottem doors of Figurese and 7. As the operative or lower flight of the conveyer moves toward the right in Fi'gure 16, itconveysmateria-lco tainedbetween thebody wheels 76- and upOII-the successive doors'I'T, '78 and 79. Thedoors are arranged in triplet's i this construction, and the rear door 79 of each tripl'etis normally sup-- ported' hy a1atch80pivoted t'othe body wall '76 aidjaeent'the door '79: During the movement of the doors the Iatch'BO encounters afixed stop 81- which causes a relative clockwise movement of. the latcliand therewith a releasing of the i w h swiilgsdownward andmoves hodil 'y irearward as hefore and thus releases the nn dmeuoon 78 which in turn bv swinging and bodily movementopens and'releases the front door 77 of th-is triplet, 'Thelading on thedoors of 'this triplet thus -is' released for dumping. The clos mg device" C operates upon the front door 77 to clos'e it into the positionshown in Fig. 16, and tdholdit iri this position temporarily. When the middle door 78* of the triplet encounters the closing deviceTO; it islikewise swung upwardly-andby encountering the foreingpiece 82 is moved bodily forward until it presents its forwardedge" beneath the rear edge of the front door 77' and h'jold's the latter in raisedposition; As the rear door (9 encounters" the closing device C, it likewiseisswung-upwardly and by'itsencounterwith' the forcing 'piecefi is moved bodily forward' intoasimilar holding positionbeneath the rear edge of 'the middle door-*78z toward the" end of its closing movement it encounters the inclined surface of the -latoh 80 andswings thelattert. A's

the-rear door 79*1eachesits closedjpositiongthe latch '80 swings hack again'and retains it against Inthe"-conveyer shown these figures, the

front door "77 is hld by e, roller E i-against down wardf dropping while in 'the upper or returrifiight:

The middledoorv78fisheld-by 'a-nose 82w formed integral with the feroingpiece e21 Therear door I9 5s likewise prevented 'fromsi ch dropping moveme'nt during the{ return flight by an angle-piece 85 which. extends:loeyond the rearedge of the rear door 79 and serves, during thelower' or operative flight, also to prevent the passage of ladinghetween thereardoor 79 of'one tripletand the front door 77 of the next succeeding triplet.

In" Fig;18", a helical chute 86 is illustrated for conveying lading" onto the operative lower flight.

It will vvbe noted that irr the several forms 'of construction; 'a plurality offdoors are provided, each ofithe doors-being independently pivotedp and" interengaging -means are provided so that each doormaihtainsthe next ,forward door in closedg-ii e. upwardly swung, position: and that 1 provided' for each that in-several instances these devicesare fixed many "of" the forms; independent devices are bodily movable door for holding 6 to the frame of the apparatus and engaged 'withf the particular door adjacentits rear edge. Insuch j devioes, thefd'oors are held in forwardly" moved position independently of the operation" of the:

next rearward door for holding it closedso that f little or' no stress retransmitted from one door to another inthe'longitudinaldirectionof the ve i hicle for the purpose" of holdingabodily movable door in forwardposition. By the provision of bo'dily movable doors, afsingle latch is enabled" to control the system of doors, and uponrelease permits a dropping movementlwhereby the pr'e' viously latched? door is enabled to escape from the element which has" previously been holding releases the next forward door for dropping without itself having swung through any considerable angle, Hence the assembly of doors is released so I that the doors of amine car, for example, may

fallupon the tiesbefore thefront door has come to; an empty portion of the bin. The doors then open successively from the front rearward, as

they move at an empty portion of the bin. No door,

is then held'in-closed position so long that it has not opened untilits lading must fall a considerable distance to the bottom of the bin. This arrangement, which" may be called a 1-2-3 order of dumping fora three-door mine car, is of great In mine cars, the frame structures are preferably 7 made verylow and close to the rails, in order advantage in the handling of such lading as coal.

to permita maximum capacity. In prior types of door controls, the rearward door was required tomove through a considerable angle before releasing thenext forward door, etc.: and hence with a low frame, the release of the-doors did notoc cur, until the rear door cleared the pile of material in the bin, so that the front door in releasing .its load permitted theload to drop a considerable distance to the bottom of the bin; and in practice from 2, to 3 percent of the lump coalv is saved by this l-2-3orderof dumping, as the coal is laid on the pile very gently and there-is practically no breakage. Inparticular, it will be noted that the present arrangement-permits the release of all doorseven though the frame structure is low,

Q by the timethat the falling edge of the rear door has, passed below the frame structure. a i

It is, obvious that many other;form s of con; struction may be' employed, and that many: "changes may be made in the door systems, as

well as in'the other parts ofthe apparatus'., 1 While the structure hasbeen described withrespect to three doors,..it is obvious thatany number may Having thus described-the invention what I claim as new and desire to'secure by Letters-'- Patent, is 5 1. A drop-bottom dump apparatus having a travelingframe, a forward door and'a'rearward;

door, parallel pivot mountings for connecting the frame and said doors whereby each: door may swing .downward at its rear edge for; opening,

said rearward door when in closed :position operating as an abutment means for preventing the.

' v opening of the forward door, means rigidly secured-to the frame for holding'said rearward door in forwardly shifted position when closed, said pivot mounting for said rearward door permittingit to shift rearward relative to the frame after a.

' short initial downward opening movement of its rearward edge below said holding means, said shifting being independent of the continued opening movement ofv the door. whereby to free 'the I forward door for opening upon a limited downward .movement of said rearward edge of the rearward door, and means for retaining said rearward door in closed position. 2, A drop-bottomdump apparatus having a traveling frame, a forward door and a rearward door parallel pivot mountings for connecting the frame and said doors whereby each door mayswing downward, at its rear edge for opening, said r arward d c yin n closed s fipn Operating Leaders; itin forwardly moved position. Thus each door';

as an abutment means for preventing the open ing of the forward door, means rigidly secured to; the frame for producing a forward shifting movementof said rearwarddoor while closing whereby it is restored when fully closed to position for holding the closed forward doorfin closed position, saidpivot mounting for said rearward door permitting it to shift rearward relative to the frame after a short initial downward opening movement of its rearward edge below said holding means, said shifting being independentof the continued opening of the doorwherebyto free theforward door for opening upon a limited downwardmovement of said rearward edge of the rearward door, and means for retaining said rearward door in closed position,

3. A drop-bottom dump apparatus having 'a traveling frame, a forward and a rearward door, parallel pivot mountings for connecting the frame and said doors whereby each door may swingdownward at its rearward edge'for opening, said rearward door when in closed position operatingas an abutment means for preventing the opening of the forward door, abutment means rigidly secured to the frame for direct engagement by a portion of therearward. door for shifting the rearward door forward during the last portion of its closing movement and for holding said rearward door forward while in its closed position, said pivot mounting for said rearward door permitting it toshift freely rearward relative to the frame independently of its opening movement after ithas become disengaged from said abutment means, so that itsrearward movement willfree the forward door for opening, and

means for retainingsaid rearward door in closed position 4.4. drop-bottom dump apparatus having a frame a plurality. of doors having transverse and longitudinally spaced pivot mountings relative tosaid frame whereby each door may swing downward at its rear edge for opening, the pivot mounting ,of -an intermediate door being construct'ed and arranged to permit said door to shift forwardly and rearwardly relative to said frame,; abutment means rigidly secured to said frame and intermediatedoor for shifting said intermediate door bodily forward relativeto the frame during the last portion of the closing movement thereof, said intermediate door being operatedi'n "closed and forwardly moved posif tion to secure the next forward door in closed position, said intermediate door being free to shift rearward relative to the frame independently of its opening movement after it has become disengaged from said abutment means, means operatedby the closing of the door next; rearward of said intermediate door for securing said intermediate door in closed and forwardly moved position, and meansfor retaining said next rearward door in its closed position.

5..A. drop-bottom dump apparatus having a frame, a plurality of doors having transverse and longitudinally spaced pivot mountings including members fixed to said frame whereby each door may .swing downward at its rearward edge for opening, the pivot mountings of two adjacent doors being constructed and arranged to permit said doors to shift relative to the frame connections of said members, independent means on said frame and each said door for shifting each said adjacent door bodily forward relative to the frame during the last portion of the closing movementthereof, each said doorbeing free for forward bodily movement independent of movement, and means for retaining said reareiti esi r es o d a portion o t e op er ing movement-and while the door is closed, and ;means for retaining, said rearward. door inits,

said rearward door is wlocated..between the side! lsillszso -:that 1 it. may. .be swung aboutlisaid trans! frame; ajforwarddoorand a rearward door, parallel .pivotmonntings forconnecting the frame.

andsaid, doors wherebyreach ,doorpmay swing downward at} its 1 rearward ,edgefor "opening, the

' 'door whereby the rearwardzdoor may operate to 1 se ur thei doorcsled ribs iom nd L position for;.holding said -forward door closed;

ment. ,-in; the ;longitudinal direction thereof: and; 1 engageablmby said.rearward-floor--during the ing movement thereof;for'.producing,a forward bodily-movement of said rearward door relative to the frameandqfor holdingsaid rearward door;

,inggsaid last portion of tits closing movement i jgframe members,;.a transverse member extending;

downward; about -their mountings, for; opening,

tion therebetween, and whereby said rearward door may be sW 1ng. "about said transversememher-into a substantially tupeside-down position,

so that it. may be slid along. said transverse mem a aara:

said meansa except; during; saidlast portion of: its-movement and thelcorresponding portion 30f the opening; movementnthe front one ofwsaid-z adja'centzdoors being operative. iI1'Q10SBd:f01r-, wardly'moved position to holdthe next forward door in closed;position,.means operated; by the closing of saidother adjacent door; for securing said; first adjacent door. in, closed and forwardly moved position, and means for retaining. said: otherwadjacent door in itsclosed position; i J 6.A dropebottom dump; apparatus havinga position for sliding ,movement rrearwardly rel-- ative to saidxside :frame'members wherebyit may be disengaged from the 'frame and removed from means.

. 10.;A drop-bottom dumpapparatusi having. side framemembers a transverse member extending betweensaid. side frame members, 'a forward members, vaarearward door located between saidandrearwardly bent hooked portion. at itsfront pivot mounting of said rearward door. permit: ting it to move bodily forward and, rearward" relativetto saidaframe, saidrearward. dQOig'DPBT- ating when in, its .;,closed and forwardly moved provide .a mounting forswinging and shifting movement. ofsaid rearward door relative to the to swing downwardly at'their rear edges about means-r eid yffix d totheframe 81g5in t= m ve. thewrearwardigdoorforward. relative to the'side ment of the. rearward door: whereby itioperates closingportion of theupward swinging and closand'means for retaining .said rearward door in its closed: and...forwardly moved position. i

.11. Ajdrop-bottomdump apparatushaving a in said forwardly moved position, said rearwarda ri being f e of Said rigid e n eXCeDt C1111 rearward; door having its front edge rebent 'to provide a channel. parallel pivot mountings on the framefor saiddoors'whereby each may swing downwardiat its rearwardedge for opening, said and the corresponding portion of theopening ward door in its closed position.

7-,Adl PTb dumpiapparatlls having Side itspivot'mountings whereby the door. may shift acrosssaid side frame members, a" forward, oor pivotally mounted at its front end for swinging movement relative to said side ,frame members, .7 a rearward doorlocated between said side frame, members and having a rearwardly, bent hooked po t n tsi m n wnea ed rou d sa transversernember wherebyJs'aid rearward door may swing and shift rel'ative to said side frame. mber both sa se eada t to. swine operating to. secure-said forward door inclosed position, and means for retaining saidirearward door in its closed and forwardly shifted position.

12. A-idrop-bottom dump apparatus having a frame, a forwardidoor a'rearwarddoor, a pivot meansior shifting the rearward: door relative to the side frame -members. during the forward v ing'andnalso to move bodily forwardYandJrearswinging movement for .elosmg of; the rearward 'W'ard relative to: saidframe, the said rearward door .xserving as i an abutment means for holding.

engaged with said rearwardfdoor-only .during the last pqrtiqn of the closing movement; her and tion, interengagingwedging devices fixed rigidly to said frame and said rearward door for. moving the? rearward door':jbodily forward relative to the'frame during its c10sing:.m0vement, and meanshfor retaining said rearward door in its cl s d and qr rd r m ved. position closed andforwa-rdly moved position.

' f8, apparatus as .in claim '7 inwhich said rearward door has the hook portion downwardly and. rearwardlyrerbent, and said transverse member andassoeiatedcar structure is so constructed and. arranged that .said rearward door cannot be disengaged from said transverse member while the door is in open or closed position or any 51.-

pivot mounting. on theframe lfor saidf-orward door1 whereby it may swing downward at its rear. edgesfor. opening, pendulummeans pivoted to the and rearward relative to said-frame, said rear.-'

berl and thereby disengageditherefrom. and rewardlyimovedposition'fon holding saidfor-ward movedfrom the apparatus: g 1 i -9. An apparatus asin fclaim ,7; including means on: said side frame, members for limiting .the. shifting movement of said rearwardsdoor when in closed and normal open positions; and wherein 14.;A drop-bottom dump: apparatus. having: a i

versetmemberinto a substantially. .upe'side-dowrr.

theapparatus without hindrance by saidlimiting door pivotally mounted at its front end for} swinging; movementrelative to said side frameend engagedaround said. transverse. member to sidesframe. members, said doors'being adapted their mountings: for opening, .means for: shifting framemembers' during the swinging closingimoveto secure "the forward door in clbsedposition,

frame, a forward door and a rearward. door,.said-s rearward door havingitsichannelengaged over:

relative to its saidzpivot mounting, said rearward doonwhen. in closed and forwardlyshifted position i ymountingon the frame for. said forward door wherebyit may. swing'downwardat its rear edge .c'for i opening: pendulum-Wmeans pivoted to' the frame and to: the "rearward door forjpermitting said rearward door to swing downward for opensaidtforward doorficlosedwhen said rearward doorzl is? in its :closedigand forwardly moved posi- 13. AI. drop-bottom dump apparatus having a frame; .a. forward door an'd'r a: rearward door, a G0 frame and toithe rearward door for permitting. said'rearwarddoor toswing downwardat its rear edge for opening and alsoto move bodily forward r ward door operating when in its closed and fori side frame members andlhaving adownwardly door closed, said rearward door interengaging with the frame. during its upward swinging movement of closing for producinga forward bodily movement of said rearward. door relative; to the. frame,- and'meansfor retainingisaid rearward. doorjinyits closedand forwardlymoved position.

frame, aforward doorand a rearward door,- a-

pivot mounting :on the frame for said forward door whereby it may swing downward atits rear edge for opening, pendulum means pivoted for movement .relative to the frame and having a" pivot connectionto the rearward door for permit-. ting said rearward door toswing downward at its rear edgefor opening and-to move bodily forward andrearward relative to said frame, said doors being interengageable when in closed positionso that the rearward door may hold said forward door. in closed position, and cooperating door-actuating elements secured to said frame and rearward door forinterengagement during up-. ward swinging'movement for closing of said rearward door whereby to move said rearward door,

bodily forward relative to the frame, and means for retainingsaid rearward door in its closed and forwardly moved position. a

15..A drop-bottom dump vehicle having a frameya transverse axle extending across said frame,,a transverse member extending across said frame and providing a diverting wall above said axle, a pendulum device pivotally mounted at the forward edge'of said member, a rearward. door pivotally mountedon said pendulum'device' for downward, swinging movement at'its rear dulum device includes means forsupporting the edge for opening and adapted to move bodily. with said pendulum device in the longitudinal direction of the vehicle, a forward door pivotally mounted on said frame and adapted-to swing downward at its rear edge for, opening, said rearward door when in closed and forwardly moved position providing an abutment for preventing the opening of said forward door, said rearward door being moved from abutment position by its opening and rearward movement, and means for retaining said;

rearward door in its closed and forwardly moved position. V I 16. A vehicle as inclaim 15 in which the penforward door vin closed position, and in which abutment forholding said pendulum'in supporting position.

17. A vehicle as in cm" 15 in which'said:re+:

taining means includes interengaging' portions of the frame and rearward door for producing 'abodily forwardmovement of said rearward door-1 during closing, and operating in the close'dposition of said door to prevent rearward. movement thereof. 1

18..A vehicle as in claim. 15 in which=said re-.

taining means includes interengaging devices on the frame and rearwardv door for'.-producing:a

during closing, said means on the door being located forwardlyof the rear edge of the door..

, 19. A vehicle as in claim 15, in which said pendulum device has a pin and slot connection-with the'rearward door for permitting the swinging and bodily movement thereof, and interengaging means areprovided on the frame and rearwardframe, an angle member extending across the frame above said axle and providing a diverting ridge thereover, a rearward door pendulum means pivotallymounted at the forward edge of said angle member and having a pin and-slot connection located beneath said ridge for supporting said rearwarddoor, whereby the rearward door may swing downward for opening, in-

terengaging means on said door and said frame position by said pendulum means when the latter is inits forwardly moved position and being free to swing downward-when'said pendulum means is in a rearward position, and means for retaining said rearward door. in its closed and forwardl moved position.

21. A vehicle as in claim 20, in which said pendulum means'has a pin and slot connection with the'rearward door for permitting the swinging and body movement thereof, and interengaging means are provided on the frame and rearward door for producinga forward movement of the door during closing, and means are provided on said rearward door below said ridge for engaging said link means 'toproduce a forward rocking movement'thereof during the forward movement of the door.

22. A'drop-bottom'dump apparatus including a' frame and front, middle and rear doors having pivotal support members adjacent their front ends, means connected to the frame for supporting and permittingthe middle door to swing downward at its rear edge for opening and also permitting forward and rearward bodily movemerit of the {door relative to the frame, means rigid with the frame and intereng'aging means associated with, saidflmiddle door whereby said middle door is forced'bodily forward relative to 7 for securing said front door in its raised position said, rearward doorwhen'retained in its closecl and forwardly moved position constitutes, an

when said'm iddle door is in its forwardly moved position; means controlled by said rearward door for securing said middle door in its closed and forwardly moved position when said rearward deer is'closed, said middle door being free for rearward bodily movement during the opening after release of said interengaging means from said frame'meana'and means for holding said rear door in'o'lo'sed position.

23. An apparatus as in claim 22, in which saidinterengaging means on the frame and middle I door comprises a device fixed to the frame, and

a cooperating device rigidly located on said middle door forwardly of its rear edge when closed. bodily forwardmovement of the rearward door 24'; A drop-bottom dump apparatus including a framean'd front, middle and rear doors having pivotal supporting members adjacent'their front ends} said middle'--door including stiffening flanges at itssides, meansconnected to the frame for supporting and permitting the middle door to swing downward atits rear edge for opening and also permitting forward and rearwardbodily movements of the door relative to the frame, interengaging means associated with the frame and middle door and including'means fixed to the frame andcobperatihg"devices located on said flanges of the middle door for engagement with said fixedmea'ns during the :closing movement of the door" for producing 'abodily forward movement thereof; interen'gaging means included in said front and middledoors for securing said front door in its raised positionwhen said middle door is initsforwardly moved position, means conto; wipe downward a ei ndyfrontom ddl amizi ean p r h ns pivotal ppe s:im mb rsvedfia entlme dean vx q u i e mt f eni ie rear ed e i 2 openi n fl o m tt g orwar and ea ward;v bod y movements of the door relativejo the jrame m e n a ms: ans a so ate wi h; thee mm 11mm m ..-fi ed to the h he; vpprti nv 9111 1 middle de w e q v whereb a d: m e; 100M iomed b di i ward: fi e te-th frame chmd on o "Pmduci-n me t c er o f ntere moved; qsitio nd m ans i po i ons.

said: f rame v means e a e rand: sa hd 62 m dd doo i lu nsvi zc tw h a he styp rtioni e 91m w ereb mpre u m1 me p Taid I 1lQid0 v. gaging means being free of one anot dur -s d ast vner en 0 tolled-p e the esp'd nqnt e m mbetl hwmi iiidQd ng; ns m i'm ddl doc li a in a dmq e wq tai itli wi e downwar i g he rr md esior peni 1,.

dl wa a domsnM- h alen i a Iwh r b Sa diddle: oor subverts a w gonr .dee n -middle en i nv iorwe d p i n wh mb sa d-rear d9" unr' i fi se middle doorQWhemsaidmear doom;

m ed osi nfier n esin nm e s nsai iaasr danwaiwae v 1 s d ng y odzv' he nea direetieil o f the frameflnterengagingmeansorggsaid (199138 m dqmpfil ive bodi mov m Qfsa oo r fremez-excepbkduring said last portion of the: clos tinsve nt and th o res on ne n of shepenin ve en zthe eo a m s r i I; ;e1osed;-- and, iorwxrdly e imm x ndf om; mid e a d bp-bo m doors interengeging meamsg on said frame and v 9r, erm t in msQ- we own a t fih i rea,r-ede essiorope n a dral q p rm t mi s hi e dendmearwa d bodil movements m mi d e and. re zz qor relat v em immefi d d mean c t edbv h r m yflor.

4 dd edp m v V. N idle: en np o e "waved memes: whena ai e o Q1 endfie werdlw mq po n,- and n nesaislwree o gin elosedend ,-;front--doo V amdrp, pivoemounting-theret v othev fl oni the 13st portion pi; its closing; movement,

Y- xi am e p e ved1 q n= ne a ins to o d x A mmb" fit mqdum a a u r 3 mme a anflp fronWw-and: iv trmq nt neh r I s gme, awpl qrglity of rearwarddoors e.nd -,pivot motingsthereior ogsaid frame wa rd doogs may swing and also 2Q 4 13 1% rea war w sa eir w rd er wh i os f i q K- insJQY' Q Q hebqdynbqtmmen in c ada ted e-swing ewnward-j tziits rea eeds t earned ihe rea bove,and ins eth r eri m n k e orwgigd reletive -tethe fremeyduring 1srmev m acha a'i :rearww .dencke prxwa y'smov d'po ine e me twh di em exv o w do m an c m si .f ca m; member @ndsap can the fiigine an thez ofilger on the door.

mbet, ne of aid members being W meansma h sa d "10 'pivctmbuminjgs therefor oa's'aid trade whereby the rearward doors may a swing and also move bodily forward and rearward with respect to said "frame, said doors whenin-olos'edposition serving toclose the body bottom andbeing each adapted to swing downward at its rear edge to discharge *the- 'lading carried thereabove, and independent interengagingmeans on each'of said; rearward doors and on the frame'for moving each door bodily forward relative to" the frameduring its 'own closingmovement,'eachsaid rearward door when in'cl'osed'and forwardly moved position operating to hold thenextforward door closed, said interengagin'g" means" comprising for each rearward door a'-cam;member and a cam'engaging member,-SaidQcam meniber being. supported on the door and said cam engaging member onthe frame: h My I 33.--A drop-bottom dump apparatus comprising 'alading body havihgafram'e and an open bottom,

"a front door and a pivot mounting therefor on said frame, a plurality of-rearward-doors and pivot mountings thereforonsaid frame whereby membenfsaid' cam memberb'eing supported on the frame and said 'canrthe dooryj" 34. A drop-bottom 'dump" apparatus comprising 'a'ladin'g body having a 'fram'e'and an open bottom, a'front doo'r and a pivot'mounting therefor on said frame; a plurality" of'rearwardj doors and pivot "mountings therefor-"1onsaid frame gaging member on whereby the-rearward doors my "swing and also move-bodily forward" and. rearward with respect to said frame, saiddoors' when in closed position serving ;to-close the body bottom and being each adapted to swing downward its'rear edge to discharge the lading carried-thereabove, and in,-

dependent intereng'aging means on each 'of' said rearward doorsand on the'frame for'moving each door bodily' forward relative 1 to the frame diiring its own*closing movement; each said rearward door whenin closed and forwardly moved position operating to hold the next forwarddoor closed, said interengaging'means comprising for leach rearward dooracam member-and a cam engaging member, said members being located adj acent the front edge of-the closed door; andfsupported one on said frame and the other on'said'door, .35.fA"drop-bo ttom dump apparatus comprising'aladi g body having'a frameand' an open bottom,a front door and a pivot mounting therefor on said-frame;apluralityof rearward doors and pivot mountings therefor on said frame 'whereby the rearward doors may swing-and also move bodily forward and rearward with respect to said'framegsaid doors when in closed position serving to' close theibod'y bottom-and being each adapted tof swin g downward 'at its rearfedge to discharge the lading carried"thereabove; indeen fix te l nsa i me ns e v l h bf i rearward doors and on the frame-for'producing a bodily forward movement of the corresponding door relative to the frame during its own closing movement; each said rearward floor when in closedand forwardly moved position operating" to hold the next forward door closed, door and frame elements of said inter-engaging means being-released from one another upon a short swinging movement of the corresponding door toward open position so that such door may thereafter move bodily rearward independently of its swinging movement and quickly release the next forward door, and means for limiting the closing movement of the doors.

36. A drop-bottom dump apparatus comprising a lading body'having a frame and an open bottom, a front door and a pivot mounting there'- for on said frame, a plurality of rearward doors and pivot mountings therefor on said frame whereby the rearward doors may swing and also move bodily forward and rearward withrespect to said frame, said doors when in closed position serving to close the body bottom and being each adapted to swing downward at its rear edge to discharge the lading carried thereabove, and independent interengaging means on each of said rearward doors and on'the frame for moving each door bodily forward relative to the frame during its own closing movement, each said rearward door when in closed and forwardly moved position-operating to hold the next forward door closed, and a plurality of means pivotally mounted with respect to the frame-and each adapted to support a door against opening, each said means being operated by the forward movement of one door as it closes into position for holding the next forward door closed and beingloperated to release the corresponding door upon a short swinging movement thereof toward open position so that such door may thereupon move bodily rearward independentlyof its swinging "movement and quickly release the next forward door; I

37. A drop-bottom dump apparatus comprising a lading body having a frame and an open bottom, a front door and a pivot mounting therefor on said frame, a plurality of rearward doors each having a rebent forward edge, said frame including pivot means-engaged with the rearward doors adjacent therebent edges thereof whereby the-rearward'doors may swing and also slide bodily forward'andrearward with 'respect to said frame, saiddoors when in closed position serving to close the body bottom and being-each adapted to swing downward at its rear edge to discharge thelading carried thereabove, Y

and independent interengaging means on each 'of said rearward doors and on the frame for producing a sliding of each door bodily forward relative to the frame during its own closing movement, each said rearward door when in closed and forwardly moved position operating to hold the next forward door closed. 38. A drop-bottom dump apparatus comprising a lading body having aframe and'an open bottom, a front door anda pivot'mounting therefor on said frame, a plurality of rearward doors each having its forward edge rebent to form a-slot,

pivot mountings on the frame engaged in said slots so that each rearward door may pivot about its mounting and may slidewith respect thereto, said doors when in closed position serving to close the body bottom and'being each adapted to swing downward at its rear edge todischarge the lading carried thereabove, and independent 'interengag'ing means on each of said' rearward I dama e szsupporting members extendingtransrerselmbe- :orri said'frame: adJacentw-s'aidsrear:membentand :havingaoforwardly andzupwardly inclined-m;-

face; forward ands; rearward;dropbottomi:doors,

linterengagina meanszsincludesaiai 1 ties rodi'com- :nected tozsaid L-frame andiextendm ,abovethcif axle, pendulum means pivotally'mountted: cm said -tie trod: iextendmgyforwardly and downwa d past the axle fors ppo tingtherear 366.8 of: thei orwa de d o ri aidwnendulum me ns rbein ie agedibyith rearwa ddgo when: in for.-

wwardlyzmoved po iti rand there h d-a ains releasingsaidforward 5 dOor L {the upward y :saidurearward door extending between said memt bersdpivdt mountings for -said-sdoors locatedrad' iaceiit their: front: edges; Stile-amounting: for said --rearward doomincluding-meansfonpermitting' a 1 4& 9P6 bo tom IQQGLiQEWWZ. andrr war cibo'dily .moveinentfof suolmdooie irra longitudinal direction? relative touthetframe:wherebyqlitamay j-moveatowa'rd-and from itheggforwardrdoorgmeans won said rearwardedoon for'zengagingwsaidacontrol :F'piece: towardiithevend bf itss-closing movement wherebga bodilyfonward movement of :said rear- *rwairdvdooris produced, :andi' crmeansg operatedu by forward: movements ofs said rearwarde .door sfor holding saida.::forward doomin closedmosition. b 40.:im1 1apparatus as in:claimt39tiiimmhicmsaid i;-

'controlaipieceiisjiproyided at eachsideijohthelframe adjacent the rear member, and said rearward'door hadEeng agi-rfg ifi'eans'iiconnected at each side ad- 5-;

jacent its rear edge. if v 41. An apparatusas in claim 39, in which the control piece projects forward of the rear edge u of the rearward door, and said engaging means terminates in front of said rear edge. u 42. A drop-bottom dump apparatus including a frame having side memberswith transversely aligned apertures therein, transverse axles pass ing through said aligned apertures, door control pieces fixed to the frame adjacent the apertures, said pieces having open-ended slots therein, a transverse rod extending between said side members and located'with its ends in saidslots, a first door pivotally mounted on said transverse rod and including a rebent portion providing a hook forengaging said rod, said door cooperating with said axle to prevent normal removalof said rod from said slots, said door being movable into substantially an up-side-down position in which it may be disengaged from said rod, said axle being withdrawable transversely through said apertures whereby to permit themovement of said rod along said slots into alignment with said i apertures so that it maybe withdrawn transversely through said apertures, and a second door supported on said side members for a downward swinging movement for opening and a bodily movement relative to the side members, said door being engageable, with said pieceduring its closing movement whereby to produce a bodily forward movement of such door.

43. In a drop-bottom dump apparatus, an open-bottom frame, transverse axles on said frame, a rearward drop-bottom door having its forward end rebent rearwardly to provide a hook for engaging over an axle whereby the door may swing and slide, a forward door having apivotal mounting on the frame for downwardmovement at its rear edge, interengaging means whereby said rearward door in its forwardly moved position will support said forward door in its closed position, and means formoving said rearward door into its forwardly moved, position during closing and for holding it in closed and forwardly moved position. I L

44. An apparatus as in claim 43, inwhich said r uri e 19 ns roneb ttemedumeia na iQQQWuPl otal. eonn i nsb t en the dorsan forward door is thereafter free to move bodily rearward relative to said frame independently of its further downward swinging movement, and interengaging means on the rearward door and the frame for limiting the rearward and opening movements of such rearward door. 7

47. A drop-bottom dump apparatus including ,an open bottom frame, forward and rearward doors, the rearward door having a downwardly and rearwardly open-ended hook at its front edge, pivotal connections between the doors and frame adjacent their front edges whereby the doors may swing downward for opening movement, said pivotal connections for the rearward door engaging in said hook'thereof, said connections permitting the doors to swing downward for opening movement and permitting individual bodily movement of said doors in the longitudinal direction of the frame, means fixed to the frame for producing a forward movement of the forward door during closing and for limiting the upward swinging movement of said forward door and operating to prevent disengagementof said hook of the reargz'ttansllersely ward door from said pivotal connection thereof,

and interengagingmeans on the rearward door and frame for limiting the rearward and opening movement of said rearward door.

48. In a drop-bottom dump apparatus, a frame, a transverse member extending across the frame, a forward door pivotallymounted adjacent its front edge on said frame for swinging downward to open, a fixed stop on the frame for limiting the upward swinging movement of said forward door, a rearward door having its front edge rebent to engage over said transverse member whereby the rearward door may swing about the axis of said member and may slide on said member, means on the frame for producing a forward sliding movementof the rearward door during its closing, and means for limiting such sliding movement, said rearward door in its closed and forwardly slid position acting to prevent the opening movement of said forward door.

49QA traveling drop-bottom dump apparatus pivot and channel permitting the forward door to swing'down atits'rear' edge for dumping and permittingit to slide with respect-to said pivot until I the pivot engages the end wall of "said'channel 'wardly moved'position-"witlr I wardpart of said-' ehanneL a rearward door,- a

"adjacent the front edge "of the forward door whereby the pivot andsaid' end-wall prevent disengagementof} the "doo'r from theframe while open for dumping, said forward- 'door being engageablewith a devi ee 'located'along the route of the'apparati s and ooperating therewith for the quick restoration Hur ing the early stagesf closing of said forward"door"ts olos'ed and forid pivot at a rearpivot on said 'fra'r'nefforfenlga'g'ing' said rearward v door adjacent thefront edge thereof'whereby the 'rearward door may-swing downat its "rear edge 'for dumping, said rearward door being engageable with saidc levio'e after the laltter has closed the forward door whereby to fnov' the rearward door into closed positiomnieans :operated'by said rearward doorin movingintoclosed'position for holding the'forward door in closed position, and means for holding the' rearwarddoo'r'in closed position;

'50: A dropmbttom uirip-apparatus having a ard-w i t e v v ig-9803943 wardlyopen' channeliatitsi'forward 'edge,"a pivot on the frame lo'cated in a rearward-part of said channel when-*theiiorward door is closed, I said front edge'of its strlicture' rebent upwardly and backwardly to provide a channeLtia pivot on the frame engaged in'a rearward part'of said channel hwhen the forward door: is closed, said pivot'a'nd channel permitting. theforward door to swing a, down at its rear edge fordumping and permitting it. toslide with respet to said pivot until the pivot engages the end wall of saidichannel whereby the pivot and said 'end: wall. prevent disengagement of the forward door from the "frame while open for dumping, said'forward door being engageable with adevice'locatedalong theroute of the apparatus and cooperating therewith for the quick restoration during-the first :part of the closing motion of said'forward door to its'closed and for.-

wardly moved position-with saidpivot at a rearward part of said channel,=a:r'earward door, a pivot on said frame-for engaging'said rearwarddoor adjacent the front edge thereof whereby therearward door-may swing downatits rear edge for dumping, said rearward door;being' engageable with said device after the. latter' has closed the forward door whereby to move. the rearward. door into closed position, means operated by said rearward "door in moving "into closed: position for holding the forward-door in closed position-and m'eans forholding'the rearward .door in closed position! v r i YSANF QRD. 

